A Delphi study of rescue and clinical subject matter experts on the extrication of patients following a motor vehicle collision

Background Approximately 1.3 million people die each year globally as a direct result of motor vehicle collisions (MVCs). Following an MVC some patients will remain trapped in their vehicle; these patients have worse outcomes and may require extrication. Following new evidence, updated multidisciplinary guidance for extrication is needed. Methods This Delphi study has been developed, conducted and reported to CREDES standards. A literature review identified areas of expertise and appropriate individuals were recruited to a Steering Group. The Steering Group formulated initial statements for consideration. Stakeholder organisations were invited to identify subject matter experts (SMEs) from a rescue and clinical background (total 60). SMEs participated over three rounds via an online platform. Consensus for agreement / disagreement was set at 70%. At each stage SMEs could offer feedback on, or modification to the statements considered which was reviewed and incorporated into new statements or new supporting information for the following rounds. Stakeholders agreed a set of principles based on the consensus statements on which future guidance should be based. Results Sixty SMEs completed Round 1, 53 Round 2 (88%) and 49 Round 3 (82%). Consensus was reached on 91 statements (89 agree, 2 disagree) covering a broad range of domains related to: extrication terminology, extrication goals and approach, self-extrication, disentanglement, clinical care, immobilisation, patient-focused extrication, emergency services call and triage, and audit and research standards. Thirty-three statements did not reach consensus. Conclusion This study has demonstrated consensus across a large panel of multidisciplinary SMEs on many key areas of extrication and related practice that will provide a key foundation in the development of evidence-based guidance for this subject area. Supplementary Information The online version contains supplementary material available at 10.1186/s13049-022-01029-x.

This section relates to the terminology utilised by the wide range of professionals attending a motor vehicle collision (MVC) and considering whether standardisation of terminology would be preferable and should be encouraged.
Standardisation of terminology in healthcare settings has been found to be beneficial in the context of patient safety and is widely encouraged by WHO, NICE and others [8].
Organisations such as JESIP encourage pan-professional language, communication and guidance to improve interoperability [9].

Terminology statements
-A multi-professional, standardised terminology should be developed and adopted to describe different extrication approaches and their variants -A multi-professional, standardised terminology should be adopted to describe risks and hazards at a scene of an entrapped casualty -A multi-professional, standardised terminology should be adopted to described how unwell and or time-critical entrapped casualties are -A multi-professional, standardised terminology should be developed and adopted to describe the entrapment status of casualties (e.g. medically trapped, physically trapped) 7

Section 2: Extrication goals and approach
Extrication, injuries and mortality Motor vehicle collisions (MVCs) are a common cause of injury and death [10]. Following a MVC, casualties that remain trapped in their vehicles have more severe injuries and are more likely to die [11].  Extrication is the process of removing casualties with known or potential injuries from their vehicles [11,12]. Rescue services have developed a wide range of techniques to enable access to casualties and extricate them from their vehicles [12]. 8

Movement mitigation
The historical approach to extrication is based on movement minimisation and mitigation, primarily to avoid exacerbating a primary spinal injury [13].
The role of small movements in this context is unknown and a challenge to accurately quantify [14].
Large or forceful movements are considered higher risk than smaller movements [15].
Many 'traditional' extrication techniques have developed with a primary focus of movement minimisation because of concerns related to the potential for excessive movement either causing or contributing to secondary spinal injury [13]. Movement minimisation during extrication comes at the expense of time, with extrications on average taking in excess of 30 minutes [16,17].
Some rescue service teaching recommends that a majority of casualties receive a traditional extrication method, as it is understood that these result in less spinal movement than other techniques [12,13].
Recently these principles have been challenged; with a number of biomechanical studies demonstrating that self-extrication may cause less movement than more traditional extrication techniques [18][19][20].

Movement by extrication type
Work to support this project has delivered powered studies comparing cervical and lumbar spine movement across a range of extrication types [21,22]. The findings for anterior posterior (AP) movement at the cervical spine are shown below. The trend in results demonstrated with AP movement is consistent across all movement directions considered. The groups considered were: Spinal injuries are infrequent in studies which consider their rate in trapped patients [11].  In the context of prevention of secondary spinal injury, those patients who may benefit from movement minimisation are those who have a spinal cord injury and do not have other time-critical injuries that may take precedence when planning an extrication. This is a rare patient group; just 232 patients over the 6 years that this study covers, or 0.5% of the 43,633 total extrications that occurred. As isolated cord injury represents a small proportion of those who are trapped, extrication principles should be reconsidered with a wider appreciation of the mortality and morbidity associated with other common injuries and injury patterns. Within our data, for example, a trapped patient is five times more likely to have a chest AIS of 3+ than a spine AIS of the same severity (Table 3). Age and (self) extrication Patients over the age of 80 are more likely to die when trapped following an MVC [23]. -Extrication goals and approach should be similar regardless of the age of a casualty

Section 3: Self-extrication
A number of studies (in healthy volunteers) have found self-extrication to be biomechanically superior (in terms of cervical and lumbar spine movement) to other extrication methods [18,19,21]. No studies have found that self-extrication is biomechanically inferior to other extrication techniques. [21] (*Error bars indicate 95% Confidence Intervals) Self-extrication is quicker than other extrication types [21].

Figure: Anterior Posterior Cervical Spine Movement and Extrication Type
The cervical spine movement associated with self-extrication is reduced by the application of a collar [22]. Collars may not be necessary for patients with and without neck injuries who may be suitable for self-extrication [14,24,25].

Figure: Mean excursion and 95% confidence intervals for anterior-posterior movement at the cervical spine[22]
Casualties have similar potential for self-extrication regardless of age: Case reports highlight that casualties even with significant injuries, including spinal injuries have the potential for self-extrication [26].
The parameters for which patients should be offered self-extrication have not been defined or validated [23].
Historical absolute movement mitigation approach to spinal immobilisation has been de-emphasised within clinical practice and guidance.
The cervical spine movement associated with self-extrication is reduced by the application of a collar [22]. Collars may not be necessary for patients with and without neck injuries who may be suitable for self-extrication [14,24,25].

Figure: Mean excursion and 95% confidence intervals for anterior-posterior movement at the cervical spine[22]
Casualties have similar potential for self-extrication regardless of age [23].

Section 7: Casualty-focused extrication and post-extrication care
There is little evidence of casualty engagement and feedback within current guidance and manuals [12,46].
The evidence for this section comes from an as yet unpublished thematic analysis of interviews from casualties who had been extricated following a motor vehicle collision.
Selected categories, codes and quotes are included in the table below to inform the Delphi panel of key themes in this area.
Reporting of accident details on social media contributes to distress for the casualty and their family.
"But I've not been strong enough to see those photos yet. I've not seen them." (6) " I had messages coming from all kinds of people that I hadn't spoken to in ages…. It was a bit overwhelming" (8) "I was shocked by the pictures" (5) Pain experience does not match patient expectation and has high inter and intra casualty variability "It started hurting after a little while but at that point, nothing hurt" (3) "If I'd known at that particular point that, y'know, how serious it was, [laughs] I might've (felt?) a bit different or even more panicky" (9) "the only bit I can remember being super painful." (8) "you know when you're in pain you know and (something's?) hurt" (7) " taking me out of the vehicle was quite quick, was painless." (9) Casualties frequently experienced a "freeze" phase after collision characterised by lack of pain and unawareness of injury. A "rescue" companion contributes to a positive emotional state in the casualty "she was gonna get out of the car, and I said to her, y'know, do you think you could stay with me? And from that moment on she didn't leave my side" (5) "And I just felt really safe" (3) "she was brilliant just talking me through it, just to take my mind off it. And just assuring me that my dad and everybody was OK" (8) "reassuring for you, then, to have somebody with you -Very. Yes. Yeah" (5) "And they were just talking about normal stuff, about my day and what I was having for lunch, and stuff. And you know, it just took my mind off it and made it a bit easier" (8) "I was going, I can't breathe, I can't breathe, I can't breathe. And she was just saying, just keep calm; you're doing well; you're fine; you're doing all right (6) Poor communication skills by rescuers led to a loss of agency by the casualty and a negative extrication experience "I was like amazed how (.) they didn't talk to me once, even the fire service or the police or (.) the ambulance service.." (7) "And I kept saying, can you please get my phone…. They're like yeah, the police are doing that, it's all sorted; police are doing it" (family communication didn't occur) "And that has [audible inhalation] that has traumatised him." (3) "I knew I had to get out the car, but I think it wasn't discussed with me how it was going to occur." (9) "they should've just like listened to me instead of like making their own assumptions." (7) "they didn't tell me that they were cutting the car open. So I started panicking even more." (7) "And he'd got a visor on. Because I was like lying on the floor. It would've been nice to see somebody's face." (2) Explanations, warmth and human communication with casualty and family contributed to a positive extrication experience "Made sure I was nice and warm. (.) I think they were brilliant." "you're in a car, just after an accident, you still need that reassurance that nothing else is gonna happen." (7) "especially when they said they'd take care of my dog, which was my top priority." "They told me whenever they were going to do anything what they were going to do, why they were gonna do it" "once I had the information to put that at rest, I felt, y'know, that that was alleviated" Early dispatch of appropriate resources to MVCs is associated with improved system performance and patient outcome [29,[47][48][49][50].

Section 9: Audit standards and research
Pan/multi professional audit standards have not yet been developed.
TARN collects entrapment status -this is variably completed and limited to trapped / not-trapped [11].
The government report national extrication data (type and time) -this cannot currently be linked to casualty injury or outcome data [53].